PostProcessStageCollection

环境光遮挡模拟环境光的阴影。当表面接收到光时，无论光的位置如何，这些阴影总是存在。 Ambient occlusion simulates shadows from ambient light. These shadows would always be present when the surface receives light and regardless of the light's position.

制服具有以下属性： The uniforms have the following properties:

• intensity 是一个标量值，用于以指数方式使阴影变亮或变暗。值越高，阴影越暗。默认值为 is a scalar value used to lighten or darken the shadows exponentially. Higher values make the shadows darker. The default value is 3.0.
• bias 是表示角度（以弧度表示）的标量值。如果样本法线与相机矢量之间的点积小于该值，则采样将在当前方向停止。这用于去除近平面边缘的阴影。默认值为 is a scalar value representing an angle in radians. If the dot product between the normal of the sample and the vector to the camera is less than this value, sampling stops in the current direction. This is used to remove shadows from near planar edges. The default value is 0.1.
• lengthCap 是表示长度（以米为单位）的标量值。如果当前样本到第一个样本的距离大于该值，则在当前方向停止采样。默认值为 is a scalar value representing a length in meters. If the distance from the current sample to first sample is greater than this value, sampling stops in the current direction. The default value is 0.26.
• directionCount 是光线行进搜索遮挡物的方向数。默认值为 is the number of directions along which the ray marching will search for occluders. The default value is 8.
• stepCount 是光线沿每个方向行进的步数。默认值为 is the number of steps the ray marching will take along each direction. The default value is 32.
• randomTexture 是一个纹理，其中红色通道是 [0.0, 1.0] 中的随机值。默认值为 is a texture where the red channel is a random value in [0.0, 1.0]. The default value is undefined。需要设置该纹理。 . This texture needs to be set.
• ambientOcclusionOnly 是一个布尔值。当 is a boolean value. When true，只有生成的阴影才会写入输出。当 , only the shadows generated are written to the output. When false，输入纹理通过环境光遮挡进行调制。这是一个有用的调试选项，用于查看更改统一值的效果。默认值为 , the input texture is modulated with the ambient occlusion. This is a useful debug option for seeing the effects of changing the uniform values. The default value is false.

启用后，此阶段将先于所有其他阶段执行。 When enabled, this stage will execute before all others.

绽放效果增加了发光效果，使明亮区域更亮，使黑暗区域更暗。 A bloom effect adds glow effect, makes bright areas brighter, and dark areas darker.

本阶段有以下制服： This stage has the following uniforms: contrast, brightness, glowOnly, delta, sigma, 和 , and stepSize.

• contrast 是 [-255.0, 255.0] 范围内的标量值，会影响效果的收缩。默认值为 is a scalar value in the range [-255.0, 255.0] and affects the contract of the effect. The default value is 128.0.
• brightness 是一个标量值。输入纹理 RGB 值转换为色调、饱和度和亮度 (HSB)，然后将该值添加到亮度中。默认值为 is a scalar value. The input texture RGB value is converted to hue, saturation, and brightness (HSB) then this value is added to the brightness. The default value is -0.3.
• glowOnly 是一个布尔值。当 is a boolean value. When true，仅显示发光效果。当 , only the glow effect will be shown. When false，发光将添加到输入纹理中。默认值为 , the glow will be added to the input texture. The default value is false。这是一个调试选项，用于在更改其他统一值时查看效果。 . This is a debug option for viewing the effects when changing the other uniform values.

delta, sigma, 和 , and stepSize 与以下属性相同 are the same properties as PostProcessStageLibrary#createBlurStage。模糊应用于图像生成的阴影，使其更加平滑。 . The blur is applied to the shadows generated from the image to make them smoother.

启用后，此阶段将先于所有其他阶段执行。 When enabled, this stage will execute before all others.

启用后，此阶段将在所有其他阶段之后执行。 When enabled, this stage will execute after all others.

一旦对象被销毁，就不应再使用；调用除 Once an object is destroyed, it should not be used; calling any function other than isDestroyed 将导致 will result in a DeveloperError 例外。因此，分配返回值（ exception. Therefore, assign the return value (undefined) 到对象，如示例中所做的那样。 ) to the object as done in the example.

如果该对象被破坏，则不应使用它；调用除 If this object was destroyed, it should not be used; calling any function other than isDestroyed 将导致 will result in a DeveloperError exception.